# Sentence Embedding with OpenAI

*author: Junjie, Jael*

<br />

## Description

A sentence embedding operator generates one embedding vector in ndarray for each input text.
The embedding represents the semantic information of the whole input text as one vector.
This operator is implemented with embedding models from [OpenAI](https://platform.openai.com/docs/guides/embeddings).
Please note you need an [OpenAI API key](https://platform.openai.com/account/api-keys) to access OpenAI.

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## Code Example

Use the pre-trained model ''
to generate an embedding for the sentence "Hello, world.".

*Write a pipeline with explicit inputs/outputs name specifications:*

```python
from towhee import pipe, ops, DataCollection

p = (
    pipe.input('text')
        .map('text', 'vec', 
             ops.sentence_embedding.openai(model_name='text-embedding-ada-002', api_key=OPENAI_API_KEY))
        .output('text', 'vec')
)

DataCollection(p('Hello, world.')).show()
```

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## Factory Constructor

Create the operator via the following factory method:

***sentence_embedding.openai(model_name='text-embedding-ada-002')***

**Parameters:**

***model_name***: *str*

The model name in string, defaults to 'text-embedding-ada-002'. Supported model names:
- text-embedding-ada-002
- text-similarity-davinci-001
- text-similarity-curie-001
- text-similarity-babbage-001
- text-similarity-ada-001

***api_key***: *str=None*

The OpenAI API key in string, defaults to None.

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## Interface

The operator takes a piece of text in string as input.
It returns a text emabedding in numpy.ndarray.

***\_\_call\_\_(txt)***

**Parameters:**

***text***: *str*

​	The text in string.

**Returns**:

*numpy.ndarray or list*

​	The text embedding extracted by model.

<br />

***supported_model_names()***

Get a list of supported model names.